On this page is some more
igneous rock information.
Igneous rocks are the only type of rocks that form from molten magma.
They have either an interlocking, a glassy, or a fragmental texture.
They form under the water at mid-ocean ridges; within continental
rifts, in volcanic arcs and at volcanic hot spots.
rocks form under the Earth's surface where they make igneous
intrusions such as sills, dikes, plutons and laccoliths.
rocks form above the surface where they turn into rock when
lava solidifies. They can be either formed from an explosive
stratovolcano or a relatively calm lava flow from a shield volcano